Fa-Zuo Wang

Halogenated anthraquinones from the marine-derived fungus Aspergillus sp. SCSIO F063.

Metabolomic investigations focusing on the marine-derived fungus Aspergillus sp. SCSIO F063 have unveiled seven new chlorinated anthraquinones (1-7) related to averantin, together with five known analogues (11-15) when the fungus was fermented using sea salt-containing potato dextrose broth. Through the addition of sodium bromide to the broth, two new brominated anthraquinones (8, 9) and one new nonhalogenated anthraquinone (10) were obtained from the fungal mycelia. Their structures were elucidated by extensive spectroscopic analyses including MS and 1D and 2D NMR data. One metabolite, 6-O-methyl-7-chloroaveratin (2), displayed inhibition activity against three human tumor cell lines, SF-268, MCF-7, and NCI-H460, with IC(50) values of 7.11, 6.64, and 7.42 μM, respectively.

Antiviral Merosesquiterpenoids Produced by the Antarctic Fungus Aspergillus ochraceopetaliformis SCSIO 05702

Five new highly oxygenated α-pyrone merosesquiterpenoids, ochraceopones A-E (1-5), together with one new double bond isomer of asteltoxin, isoasteltoxin (6), and two known asteltoxin derivatives, asteltoxin (7) and asteltoxin B (8), were isolated from an Antarctic soil-derived fungus, Aspergillus ochraceopetaliformis SCSIO 05702. Their structures were determined through extensive spectroscopic analysis, CD spectra, quantum mechanical calculations, and X-ray single-crystal diffraction. Ochraceopones A-D (1-4) are the first examples of α-pyrone merosesquiterpenoids possessing a linear tetracyclic carbon skeleton, which has not been previously described. All the isolated compounds were tested for their antiviral, cytotoxic, antibacterial, and antitubercular activities. Among these compounds, ochraceopone A (1), isoasteltoxin (6), and asteltoxin (7) exhibited antiviral activities against the H1N1 and H3N2 influenza viruses with IC50 values of >20.0/12.2 ± 4.10, 0.23 ± 0.05/0.66 ± 0.09, and 0.54 ± 0.06/0.84 ± 0.02 μM, respectively. A possible biosynthetic pathway for ochraceopones A-E (1-5) was proposed.

Six new ergosterols from the marine-derived fungus Rhizopus sp

Six new ergosterols, including 3beta-hydroxyl-(22E, 24R)-ergosta-5,8,22-trien-7,15-dione (1), 3beta-hydroxyl-(22E, 24R)-ergosta-5,8,14,22-tetraen-7-one (2), 3beta,15beta-dihydroxyl-(22E, 24R)-ergosta-5,8(14),22-trien-7-one (3), 3beta,15alpha-dihydroxyl-(22E, 24R)-ergosta-5,8(14),22-trien-7-one (4), 3beta-hydroxyl-(22E, 24R)-ergosta-5,8(14),22-trien-7,15-dione (5), and 5alpha,8alpha-epidioxy-23,24(R)-dimethylcholesta-6,9(11),22-trien-3beta-ol (6), have been isolated from the marine-derived fungus Rhizopus sp., along with four known ones (7-10). The structures of the new compounds were determined on the basis of extensive spectroscopic data. All compounds were evaluated for their cytotoxic activities on P388, A549, HL-60, and BEL-7420 cell lines by the MTT and SRB methods.

A New Cytotoxic Sesquiterpene Quinone Produced by Penicillium sp F00120 Isolated from a Deep Sea Sediment Sample

A new fungal strain, displaying strong toxic activity against brine shrimp larvae, was isolated from a deep sea sediment sample collected at a depth of 1300 m. The strain, designated as F00120, was identified as a member of the genus Penicillium on the basis of morphology and ITS sequence analysis. One new sesquiterpene quinone, named penicilliumin A (1), along with two known compounds ergosterol (2) and ergosterol peroxide (3), were isolated and purified from the cultures of F00120 by silica gel column, Sephadex LH-20 column, and preparative thin layer chromatography. Their structures were elucidated by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analysis as well as comparison with literature data. The new compound penicilliumin A inhibited in vitro proliferation of mouse melanoma (B16), human melanoma (A375), and human cervical carcinoma (Hela) cell lines moderately.

Cytotoxic indole diketopiperazines from the deep sea-derived fungus Acrostalagmus luteoalbus SCSIO F457

Two new indole diketopiperazines, namely luteoalbusins A-B (1-2), along with eight known ones (3-10), were isolated from the fungus Acrostalagmus luteoalbus SCSIO F457 originated from deep-sea sediment. Their structures were determined by 1D/2D NMR, MS, and CD data analyses. Each of these compounds was evaluated for their cytotoxic activities against SF-268, MCF-7, NCI-H460, and HepG-2 cell lines, and compounds 1-5 showed significant cytotoxicties against all four cancer cell lines. Moreover, new compounds 1 and 2 had more potent cytotoxicity than the other ones and cisplatin.

Three New Cytochalasins from the Marine-Derived Fungus Spicaria elegans KLA03 by Supplementing the Cultures with L- and D-Tryptophan

Three new cytochalasins Z21–Z23 (1–3, resp.), together with five analogs, 4–8, were isolated from Spicaria elegans KLA03 by the OSMAC (one strain‐many compounds) approach with adding L‐ and D‐tryptophan during its cultivation. The structures of new cytochalasins were elucidated on the basis of comprehensive 1D‐ and 2D‐NMR and HR‐ESI‐MS analyses. Cytochalasins Z21 and Z22 (1 and 2, resp.), and compound 5 showed cytotoxic activities against A‐549 cell lines with IC50 values of 8.2, 20.0, and 3.1 μM, respectively.

Mangrovibacterium diazotrophicum gen. nov., sp. nov., a nitrogen-fixing bacterium isolated from a mangrove sediment, and proposal of Prolixibacteraceae fam. nov.

A nitrogen-fixing bacterium, designated strain SCSIO N0430(T), was isolated from a mangrove sediment sample. Analysis of the sequence of the nifH gene responsible for nitrogen fixation in this strain indicated a close relationship to an uncultured bacterium ZNZ-D11 (GenBank accession no. JF896696). 16S rRNA gene sequence analysis revealed that this isolate had less than 93 % similarity to its closest relative, Sunxiuqinia elliptica DQHS4(T). A phylogenetic tree reconstructed based on 16S rRNA gene sequences revealed that strain SCSIO N0430(T) was a member of the phylum Bacteroidetes. Chemotaxonomic and physiological characteristics, including phospholipids and major fatty acids, readily distinguished the isolate from established members of the phylum Bacteroidetes. It is concluded that strain SCSIO N0430(T) represents a novel genus and species, for which the name Mangrovibacterium diazotrophicum gen. nov., sp. nov. is proposed, with the type strain of the species SCSIO N0430(T) ( = KCTC 32129(T) = DSM 27148(T) = JCM 19152(T)). Based on phylogenetic characteristics and 16S rRNA gene signature nucleotide patterns, the three genera Sunxiuqinia, Prolixibacter and Mangrovibacterium are proposed to make up a novel family, Prolixibacteraceae fam. nov., in the order Bacteroidales.

Antifungal New Oxepine-Containing Alkaloids and Xanthones from the Deep-Sea-Derived Fungus Aspergillus versicolor SCSIO 05879

Phytopathogenic fungi remain a continuous and huge threat in the agricultural fields. The agrochemical industry has made great development of the use of microbial natural products, which has been regarded as an effective strategy against phytopathogenic fungi. Antifungal bioassay-directed fractionation was used to isolate two new oxepine-containing alkaloids (1 and 2), two new 4-aryl-quinolin-2-one alkaloids (3 and 4), and four new prenylated xanthones (5-8) from the deep-sea-derived fungus Aspergillus versicolor SCSIO 05879. Extensive NMR spectroscopic analysis, quantum mechanical calculations, and X-ray single-crystal diffraction were used to elucidate their structures, including their absolute configurations. Versicoloids A and B, versicone A, and cottoquinazoline A showed antifungal activities against three phytopathogenic fungi. The antifungal activities of these bioactive compounds strongly depend on the fungal species. Especially versicoloids A and B showed strong fungicidal effect (MIC of 1.6 μg/mL) against Colletotrichum acutatum, compared with that of the positive control cycloheximide (MIC of 6.4 μg/mL). The results of antifungal experiments indicated that versicoloids A and B may be regarded as candidate agents of antifungal agrochemicals.

A New Triterpenoid Saponin from Abrus precatorius Linn

A new triterpenoid saponin, 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl subprogenin D (1), together with six known triterpenoids: subprogenin D (2), abrusgenic acid (3), triptotriterpenic acid B (4), abruslactone A (5), abrusogenin (6) and abrusoside C (7) were isolated from the leaves and stems of Abrus precatorius. Their structures were elucidated on the basis of physical and NMR analysis, respectively. Compounds 5 and 6 showed moderate cytotoxicity against MCF-7, SW1990, Hela, and Du-145 cell lines. Compounds 1, 2 and 4 were isolated from this plant for the first time.

Pseudonocardia antitumoralis sp nov., a deoxynyboquinone-producing actinomycete isolated from a deep-sea sediment

An aerobic actinomycete, designated SCSIO 01299(T), was isolated from a deep-sea sediment collected from the northern South China Sea at a depth of 3258 m. The isolate was found to be a natural producer of the synthesized antitumour agent deoxynyboquinone and its three new derivatives, pseudonocardians A, B and C. A blast search based on almost-complete 16S rRNA gene sequences showed that strain SCSIO 01299(T) had high sequence similarities with members of the genus Pseudonocardia. The 16S rRNA gene sequence phylogenetic tree revealed that strain SCSIO 01299(T) was a member of the genus Pseudonocardia. Phenotypic analysis, chemotaxonomy and DNA-DNA relatedness could readily distinguish the isolate from established members in this genus. It was concluded that strain SCSIO 01299(T) represents a novel species, for which the name Pseudonocardia antitumoralis sp. nov. is proposed. The type strain is SCSIO 01299(T) ( = DSM 45322(T)  = CCTCC M 2011255(T)).